1. at about what temperature will 100 g of water dissolve equal amounts of potassium chloride
and barium hydroxide?

Dissolving of solute in a particular solvent depends upon the temperature of the solvent.

Explanation:

Solubility is a amount of solute that can be dissolved in fixed amount of solvent at a particular temperature. It is crucial that the amount of solvent remains constant when a solubility of a substance determined .Here the amount of solvent (water) is kept constant at (100 ml). The variable that is changed the temperature of the solvent.

  Suppose a solution able to hold more solute at a particular temperature is unsaturated. A solution is able to hold maximum solute at a particular temperature is saturated. Under certain conditions a solution hold more solute than the maximum  amount at a particular temperature is supersaturated solution. Regarding the dissolving of barium hydroxide and potassium chloride is clearly given in a table which is attached.